Sander recommendation

[Tim Watts]

I have a very old green Bosch rectangular jobbie. But it is not very effective for aggressive removal.

OTOH a belt sander would probably be *too* aggressive.

The immediate applications are:

1) Finishing rough sawn timber pillars, beam and purlins that will be exposed rather than plasterboarded over - minimal clogging risk, using fairly course paper. Furniture finish not required.

2) Removing some "stain" type finish from gutterboards prior to refinishing.

I'm thinking a circular sander that actually rotates, prefereably with some randomness, would be more effective that a vibrating plate type. Is that what "random orbital" means? Sorry, being thick...

[Jim K]

mmm circulars leave er circular marks?

Gotta say I;d be picking up my belt sander for both of those tasks, & a proper 3M style respiratory "that works" & a selection of grades of belt.

Also being beams - presumably you;ll be working overhead? so weight/ speed/fatigue would be factors?

Cheers Jim K

[polygonum]

I am impressed by my random orbital (Bosch). Not particularly aggressive but capable of quite a lot of removal. Choice of both speed and discs makes a big difference (not always using fastest speed for optimum results).

Mine is the traditional sort and a bit heavy for using in some circumstances. So maybe consider a smaller palm sander - no experience so hoping others answer.

Also, Screwfix currently offering an Evolution mini belt sander on some "special". Again, no experience.

[Tim Watts]

Hi,

Is that a blue or a green? Out of interest, does it actually spin or just vibrate in place?

When I checked wonkypedia, it said "random oribital" means an elliptical motion, so that the same piece of grit follows a diferent path on each rotation.

However, I'm not convinced that if I just go and buy a "random orbital" that it would be guaranteed to be like this.

Just wondering if I need to double check...

I'm happy with anything - probably a standard 125mm would be OK.

Cheers!

Tim

[Dave Liquorice]

Yes the sanding disc is atached to a plate that rotates (at high speed when not loaded(*)) but that drive is not central or direct to the plate. ie. the plate is free to revolve at all times without driving or being driven by the motor. I'm not sure of the mechanics.

Up shot is there is no regular circular pattern of any point like there is with a plate sander and no direction of sanding like there is with a belt sander.

A random orbital sander is quite good a bulk removal and doesn't have to be orientated along the grain like a belt sander. For your beams, pillars and purlins that means you can sand right into a inside corner without risking the nose hitting the other beam or WHY or leaving a narrow unsanded gap into the corner.

I've a Performance Power one, cheap does the job, had to reconnect a wire inside after the cheap crimp tag broke. *Much* better than any plate sander I've had.

(*) If you do let it spin up to high speed before contacting the work bring it into contact slowly and moving so that it doesn't make a cresent mark on the work.

[geraldthehamster]

Tim, what I did sounds very similar to what you're doing. I stripped out and re-did the first floor of my dormer bungalow (it was a chalet bungalow beofre we put the dormers in), and left not only the purlins but also the ceiling joists exposed (putting the ceiling back above them). I dont think an orbital sander would be up to the job - I used a Makita belt sander, starting at 60 grit, then 80, then finishing off with 120. I must have taken off a good 1/8 inch before the risk of splinters in fingers was removed.

Cheers Richard

[Dave Plowman (News)]

Sadly, the only sander which will do this in a reasonable time is a belt type.

Random orbit ones sort of rotate about two axis. Less prone to scratching than plain rotary types.

[GMM]

I rather suspect you might need both variants. I've always found my belt sander very aggressive, so probably good for your rough timbers (used carefully of course). On the other hand, I've always been happy with my random orbital for finishing and with a coarse disk it will take quite a lot off a surface. Sadly, I bought a B&Q jobbie because it was cheap and I thought I might only need it the once. If I had anticipated how good it is (compared with 1/4 sheet sanders etc), I would have been persuaded to get a better brand. Being a bit of a tightwad though I can never (or rarely at least) bring myself to buy a new tool when the old one is working.

The only thing I wonder about with either is how they will suit working on fixed timbers (presumably vertical and above head height in places). Both of mine are pretty heavy and I wouldn't fancy working too high with them for any extended period. Maybe I'm just getting old, to even think of that (!)

[dennis]

I don't think random orbital means they rotate. i have a rectangular random orbital and it doesn't rotate.

I also have a bosch circular one and that rotates slowly.

On both the centre of the plate does random orbits around a fixed point (relative to the rest of the sander).

[Tim Watts]

Thanks Dave - that sounds just the job!

Basically, I am going to de-plasterboard the entire dormer conversion, stick more celotex in and re-model the space slightly (in a non structural way).

The upshot is I will have 2 3x3" pillars exposed rather than hidden in a drywall, the central roof beam will be half visible rather than boxed in and I *might* allow some of the other timber structure to be on show. So a lot of sanding is in order :)

[Tim Watts]

I hear what you are saying.

Ah - I understand now...

Thanks!

[Jules Richardson]

Hmm, if the wood's "nothing special" and the aim's just to have some timber on show, then could you perhaps clad it in something that needs a little less work?

cheers

Jules

[Dave Liquorice]

They do.

You are confusing the marketing terms "orbital" and "random orbital".

That'll be a random orbital type.

And on a random orbital one the whole plate is also free to rotate. This doesn't happen with an orbital sander.

[John Rumm]

A belt sander would probably be quite well suited.

Also people often fail to use an aggressive enough paper to start with. You are much better off starting with say 40 or 60 grit and getting everything basically level quickly, and then working up the grits fairly quickly where all you now need do is remove the sanding scratches left by the previous grit.

Belt, and keep it moving. Possibly finish with a random orbit.

Same again.

Yup basically; a cross between a orbital and a disc sander...

Details of the various types here:

[John Rumm]

Generally they do however... In fact I don't think I have ever seen one that does not.

Its probably just an orbital then...

What make / model?

PEX400 probably - that's a random orbit jobbie.

Random orbit sanders usually do regular orbits around a rotating off centre point.

[John Rumm]

Its what ebay is for ;-)

Its worth thinking about certainly... especially if you can elevate yourself to a point where you don't need to work at arms reach. There are times its easier to go for a small single hand held sander that will take longer but cause less fatigue overall.

[polygonum]

Well mine is a PEX400 (I think!) - and it always appears to me that the base works a bit like a spirograph. There are certainly some which *** claim *** to be random, orbital and rectangular but scepticism runs deep.

[dennis]

That would require me to go looking for it in the shed. The shed has been taken over by empty and part empty xmas decoration boxes so its not going to happen unless there is an emergency. Its been so long since I used it I don't even recall the colour.

[Tim Watts]

Maybe I do need to try a belt sander first...

Cheers,

Tim

[John Rumm]

Yup, that's the norm for RO... the relationship between rotation and orbit action is not hard geared as such, but driven by some form of clutch I believe.

You could probably do it with a pair of orbital mechanisms mounted one upon another, geared at slightly different speeds.